MB39A132QN-G-ERE1 Fujitsu Semiconductor America Inc, MB39A132QN-G-ERE1 Datasheet - Page 38

• Manufacturer Part Number: MB39A132QN-G-ERE1
• Description: IC CONV DC-DC LI-ION 32QFN
• Manufacturer: Fujitsu Semiconductor America Inc

Specifications of MB39A132QN-G-ERE1

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Operating Temperature: 25°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 865-1020

MB39A132
38
• Fly-back diode selection
In general, the fly-back diode is not necessary. However, if conversion efficiency becomes a major concern,
it can be improved by adding a fly-back diode.
Select a Schottky barrier diode (SBD) that has a small forward voltage drop.
Since this DC/DC converter control IC adopts synchronous rectification, the length of the time in which
current flows through a fly-back diode is limited by the synchronous rectification period. Therefore, select a
fly-back diode whose current does not exceed the rated peak forward surge current (IFSM). The peak forward
surge current value of the fly-back diode can be found by the following formula.
The rating of a fly-back diode can be found by the following formula.
V
R_Fly
I
FSM
I
I
ΔIL : Inductor ripple current peak to peak value [A]
V
V
FSM
OMAX
R_Fly
IN
> V
≥ I
: Rated value of fly-back diode peak forward surge current [A]
: Maximum charge current [A]
: DC reverse voltage of fly-back diode [V]
: Switching power supply voltage [V]
OMAX
IN
+
ΔIL
2
DS04–27265–3E